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Category: materials – Page 61

Researchers at Mainz University have been able to visualize the third class of magnetism, called altermagnetism, in action.

Ferromagnetism and antiferromagnetism have long been known to scientists as two classes of magnetic order of materials. Back in 2019, researchers at Johannes Gutenberg University Mainz (JGU) postulated a third class of magnetism, called altermagnetism. This altermagnetism has been the subject of heated debate among experts ever since, with some expressing doubts about its existence.

Recently, a team of experimental researchers led by Professor Hans-Joachim Elmers at JGU was able to measure for the first time at DESY (Deutsches Elektronen-Synchrotron) an effect that is considered to be a signature of altermagnetism, thus providing evidence for the existence of this third type of magnetism. The research results were published in Science Advances.

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Whether matter could engender cogitation was a very divisive topic of early modern reflection. In his polemic with Descartes, Gassendi appeared to endorse a ‘materialistic’ understanding of cognition. Two objections by Gassendi were particularly relevant to this claim: he challenged the distinction between imagination and intellect, and argued that animal and human cognition only differed quantitatively. Since the intellect was traditionally seen as immaterial, while the imagination was understood as a bodily faculty, these claims appeared to entail a naturalized image of the human soul, and the potential that matter could generate cogitation. Here, I argue that Gassendi’s claims were not only a result of his polemical vein against Descartes; rather, they were part of an intellectual agenda that Gassendi had been pursuing since the early 1620s. I then analyse Gassendi’s change of perspective in Animadversiones (1649) and Syntagma philosophicum (1658), where Gassendi presented arguments for the immateriality of the intellect and its true distinction from the imagination. I argue that Gassendi’s early objections against Descartes provided him with material to revise his own position on these subjects. I then show some of the implications of such a change of heart. Lastly, I address some hypotheses of its cause.

Whether matter in general, and vital matter in particular, could engender cogitation was a much-discussed and divisive topic of early modern reflection. Crucial to this debate was the issue of the distinction between animal and human thinking faculties. Generally, both men and animals were believed to possess imagination or phantasy—a faculty that was seen as depending on the body. Conversely, only men could perform higher thinking by virtue of their possession of the intellect; in turn, this was commonly identified with an operation of the immaterial soul. However, early modern authors sometimes downplayed these distinctions, for instance by presenting a purely materialistic explanation of the soul and of its functions. In doing so, they brought attention, whether explicitly or implicitly, to the ability of vital matter to generate cognition.

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A material coating, whose light refraction properties can be precisely switched between different states, has been developed by an interdisciplinary research team from the Chemistry and Physics departments at the University of Jena. The team, led by Felix Schacher, Sarah Walden, Purushottam Poudel, and Isabelle Staude, combined polymers that react to light with so-called metasurfaces.

This innovation has led to the creation of new optical components that could potentially be used in . Their findings have now been published in the journal ACS Nano.

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Self-assembled solidifying eutectic materials directed by a template with miniature features demonstrate unique microstructures and patterns as a result of diffusion and thermal gradients caused by the template. Despite the template trying to force the material to solidify into a regular pattern, when the template carries a lot of heat it also can interfere with the solidification process and cause disorder in the long-range pattern.

Researchers at the University of Illinois Urbana-Champaign and the University of Michigan Ann Arbor have developed a template material that carries almost no heat and therefore stops between the template material itself and the solidifying eutectic material. They accomplished this by forming the template from a material with very low thermal conductivity, ultimately resulting in highly organized self-assembled microstructures.

The results of this research were recently published in the journal Advanced Materials.

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A 3D printed ‘metamaterial’ boasting levels of strength for weight not normally seen in nature or manufacturing could change how we make everything from medical implants to aircraft or rocket parts.

RMIT University researchers created the new metamaterial—a term used to describe an with not observed in nature—from common titanium alloy.

But it’s the material’s unique lattice structure design, recently revealed in the journal Advanced Materials, that makes it anything but common: tests show it’s 50% stronger than the next strongest alloy of similar density used in aerospace applications.

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When red giant stars run out of helium fuel and expel their outer layers to become hot, compact white dwarf stars that are roughly the size of Earth, planetary nebulae are created. As the carbon-enriched shed material is gradually blasted into the interstellar medium, it produces magnificent patterns.

The majority of planetary nebulae are circular, but others, like the well-known “Butterfly Nebula,” have an hourglass or wing-like appearance. These structures are thought to be the consequence of the material expanding into two lobes or “wings” due to the gravitational attraction of a second star circling the parent star of the nebula. The wings develop over time without altering their initial form, much like an expanding balloon.

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A strange phase of matter that previously existed purely in the realm of theory has finally been detected in a real material.

It’s known as the Bragg glass phase – a strange, seemingly paradoxical arrangement of atoms in a glass material where the particles are nearly as ordered as those in a perfect crystal. Scientists weren’t even sure Bragg glass existed, but there it was, hiding in an alloy of palladium inserted between layers of terbium and tellurium (PdxErTe3).

The discovery, led by physicist Krishnanand Mallayya of Cornell University and published in Nature Physics, not only sheds light on the way materials can behave but demonstrates a powerful new set of techniques for probing the atomic structures of exotic materials.

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A protoplanetary disk is a disk of dense gas and dust, orbiting a newly formed star. It is assumed that planets are born by the gradual accumulation of material in such a structure, therefore discoveries and studies of protoplanetary disks are essential for improving our understanding of planetary formation processes.

Now, a team of astronomers led by Ciprian T. Berghea of the U.S. Naval Observatory (USNO) in Washington, DC, has discovered a new disk of this type that is associated with an infrared source known as IRAS 23077+6707. The finding was made by inspecting the Pan-STARRS data while working on a variability study of active galactic nuclei (AGN) candidates.

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